a white house official says the obama administration has been briefed on the situation. they continue monitoring local and state response through the federal emergency management agency. in addition to tending to those who have been injured, officials are concerned about the possibility of a secondary explosion. a texas state official gave a briefing early this morning and said that, quote, there are still active ingredient there's. and that the fire continued to burn. with active ingredients, we can only assume he means dangerous chemicals that could lead to a secondary explosion. to the force of that blast. it was felt, reportedly, as far as 70 miles away. our own charles hadlock, was 60 miles away at the time. and he felt that explosion. and one official who got an opportunity to survey some of the damage said it was massive. the damage was massive. it looked just like iraq. and looked just like the oklahoma city bombing. that's how severe that damage was. again, residents have been told to evacuate from nearby areas. and those who are in the area who have not evacuat